One of these day's I'll take this neat old whimsy accessory off the display shelf and install it on one of our T's. This unit clamps over a standard Model T tail light fixture. When you pull the cable the STOP stencil comes down over the tail light lens.

Wow, what a nice find! Although I guess the bulb is died a long time ago? What will you use to replace it? I would advise some kind of LEDs with a bit of coloring to them from https://www.expresslightbulbs.com/

Jay, in this time and day of crazy drivers, that type of stop light that blocks the only red light to the rear would not be what I want. It is an a need accessory, but probably best left on the display shelf. Maybe used for day driving only??????